Theme: not bad; you're discovering new planets, new mechanics, and new story.
Fun: the pacing (I think that's the right word here?) feels a little off. Levels take a long time to complete and I don't have a good sense of how much progress I've made in terms of how many levels I've done and how many more there are. This might be improved with just making everything a bit faster, but without playtesting it's hard to say.
Controls: 7pri2 made good points about the issues with the controls and I agree with those points. Also, I found it hard to aim with precision because the ship's turn speed felt slow compared to the asteriods' move speed. I think this game might be better suited to mouse controls rather than keyboard controls (turning would certainly be easier that way).
Graphics: Quite charming! It helps the game feel a little more relaxed/pleasant (rather than super-detailed art which to me would make the atmosphere more tense). It conveys the necessary information plus just a little more to make things look nice (for example, the shading is a nice touch), but not so much detail that's it's overwhelming. I guess what I'm saying is it feels minimalistic and I like it that way.
Audio: I did not hear any audio
Originality: this kind of gameplay doesn't usually have plot added, so that's new. Otherwise this seems pretty standard.
I had a hard time really getting into the game due to the aforementioned issues, but I think it's a solid concept and after some fixes I expect I would really enjoy it!